The present invention relates to an improved water amount controlling switch structure of water injection gun, which is further provided with a zig-zag slope face at the bottom of a push button so as to make the micro-adjustment of water amount in a more sensitive manner by way of a trigger moving in abutment against the zig-zag slope face in operation. The trigger can resume its non-operation position by a spring force as long as the spring biased push button is pressed down.
In the conventional water injection gun, the water flow is controlled by a front trigger type controlling switch. Such controlling switch can only keep a maximum water amount or shut off the water, while failing to micro-adjust water amount as necessary. This often leads to inconvenience in use of the water injection gun.
The present inventor provides for an improved water injection gun having a water amount controlling switch, as disclosed in U.S. patent application of Ser. No. 09/07,389. Such a water amount controlling switch is operated by way of a trigger 60 in association with a push button 70 which is biased by a spring 85. The operation of the Push button 70 is not in such a stepwise manner that the micro control of water discharge becomes difficult. So, it is often for an operator to repeat pressing the push button 70 to rake it move into the chamber 11 of the gun housing 10, allowing the trigger 60 to move backwards by the spring 84 to cut off water supply. Then, the trigger 60 is pressed once again to discharge water. Such repeated operations make the micro adjustment unsatisfied.